Summary of Work: The objective of these studies is to investigate the absorption, distribution and pulmonary toxicity of several novel chemicals used in the semiconductor and photovoltaic industries. Studies were conducted to evaluate the progression of pulmonary toxicity up to 28 days after administration of copper-indium diselenide (CIS), copper-gallium diselenide (CGS) and cadmium telluride (CdTe). Results indicate that CdTe was the most toxic, CIS had intermediate toxicity and CGS was the least toxic. For each compound significant chemical-related effects were observed for body and organ weights and all BALF indices. CdTe was also highly fibrogenic for the lung as indicated by histopathology, fibronectin and hydroxyproline measurements. Absorption and distribution studies support the histopathology results demonstrating that absorption from the lung is greatest for CdTe with little CGS or CIS detected in other tissues. Solubility data also correlate with the relative toxicities of these compounds; CdTe was the most soluble while CGS and CIS were sparingly soluble.